Moyes was in charge at Goodison Park for 11 years before leaving when his contract expired to replace Alex Ferguson, British football's most successful manager, at United following his fellow Scot's retirement.

While Moyes's successor, Roberto Martinez, has guided the Everton to a challenge for a Champions League place, something Moyes achieved in 2005, United have slipped into mid-table after winning the Premier League by 11 points last season.

In the first meeting between the two teams this term, Bryan Oviedo scored the only goal late on to secure a 1-0 win for Everton at Old Trafford.

The Toffees are currently nine points ahead of United but Moyes, who has said the match should not be about him in the build-up, maintains that catching his old club and gaining a Champions League spot is still possible.

"We've said we'll never give in (in terms of finishing in the top four) and we won't until we can't do that. Obviously it's nearly mathematically impossible but we're still trying to make it happen if we can," Moyes said.

"It's a tough game going to Goodison for any team at any time, as I should know, but we go there with a good away record and will try to make that work again.

"We'll be tested against a team in good form this year and we will have to play very well."

United striker Wayne Rooney is fit to face his former club after recovering from a toe injury, while Juan Mata is available again after being cup-tied for the 3-1 Champions League defeat at Bayern Munich.

Midfielder Marouane Fellaini, who followed Moyes from Everton in August, should be fit to face his old team but there are doubts over defenders Rafael and Jonny Evans.

- 'Points Everton's only concern' -

For Everton, Republic of Ireland midfielder James McCarthy is likely to return to the starting line-up after coming off the bench in the shock 3-2 defeat by Crystal Palace after a muscular injury.

Everton's Champions League chances fell out of their own hands with their loss to Palace in midweek and Martinez feels that the visit of United, with the emotion supplied by Moyes's return and the importance of the three points, makes Sunday's match his team's most significant of the campaign.

"This game is probably our biggest of the season. We know how vital the three points are and that is our only concern," said Martinez.

"Obviously, it's glamorous to see the champions at Goodison and it's great to welcome the figures that we're going to welcome and the quality of the players," the Spaniard added.

"But the three points in this period for us as a football club are more important than any aspect you can highlight in the fixture -- and I think that speaks volumes of what an impressive season it's been so far.

"I think the biggest compliment we can pay to ourselves is that the three points at this moment are more important than all the aspects that you can mention.

"There are lots of interesting angles in this game but we're going to concentrate on the fact that the only important thing on Sunday is how well we can perform over 90 minutes and how successful we can be at the end of the game."